Casco is a village in Kewaunee County, Wisconsin, United States. The population was 583 at the 2010 census. It is part of the Green Bay Metropolitan Statistical Area. The village is located within the Town of Casco. Casco is named after Casco Bay on the coast of Maine, the previous home of Edward Decker, an early logger in Kewaunee Coun…Casco is a village in Kewaunee County, Wisconsin, United States. The population was 583 at the 2010 census. It is part of the Green Bay Metropolitan Statistical Area. The village is located within the Town of Casco. Casco is named after Casco Bay on the coast of Maine, the previous home of Edward Decker, an early logger in Kewaunee County.